Control device



Oct. 26, 1937. H cu AL 2,096,792

CONTROL DEVICE Filed Sept. 15, 1932 v 2 Sheets-Sheetl jRiohnrci I'L Cutbiqg gz 7111M E.Ram3

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Oct. 26, 1937.

.R. H. CUTTING ET AL CONTROL DEVICE Filed Sept. 15, 1932 2 Sheets-Sheet 2 Richard H- Cutting William LRcucuzs IN vL- rows ATTORNLOZ$ b gcZew Patented Oct. 26, 1937 PATENT OFFICE CONTROL DEVICE Richard H. Cutting, Cleveland Heights, and William E. Raney, Shaker Heights, Ohio Application September 15, 1932, Serial No. 633,284

2 Claims.

This invention relates to control devices, more particularly adapted for use in refrigerating machines, and has for its principal object the provision of new and improved devices of this character.

In the drawings accompanying this specification and forming a part of this application we have shown, for purposes of illustration, one embodiment which our invention may assume, and in these drawings:

Figure 1 is a perspective view of an embodiment of the control device illustrated in connection with a refrigerating machine,

Figure 2 is an enlarged front elevational view of said embodiment,

Figure 3 is a vertical sectional view of the embodiment illustrated in Figure 2, and showing the device in one operative position,

Figure 4 is a vertical sectional view of a fragment of the embodiment, as shown in Figure 3, illustrating the device in another operative position,

Figure 5 is a vertical view corresponding substantially to the line 5-5 of Figure 3,

25 Figure 6 is a rear elevational view of the embodiment shown in Figure 2,

Figure '7 is a sectional view corresponding substantially to the line 1-1 of Figure 6, while Figure 8 is a diagrammatic layout of the elec- 30 trical means employed in connection with the embodiment illustrated.

The embodiment herein disclosed comprises a casing .Il, enclosing a synchronous motor adapted to be started by spinning the shaft I2,

35 and the motor I is connected in driving relation with clock mechanism I3, in the usual manner, and these parts .are carried by an angular supporting bracket I4, secured to the bottom of the casing Hi. The front wall l5 of the casing I0 is 40 recessed as at Hi to accommodate a standard clock dial |1, traversable by anhour hand l8 carried by'a shaft I3 and a minute hand 20, carried by a shaft 2|, rotatable by the clock mechanism l3 in the usual manner. The hands l8 and 20 may 45 be set by manipulation of a shaft 22 in the usual manner.

- Rigidly secured to the shaft I9 is a driving pinion 23 which meshes with a gear 24 journaled on a stud 25 carried by the bracket I4, and the stud 50 25 also rotatably carries a pinion 26 rigidly affixed to the gear 24, and the pinion 26 meshes with a gear 21 journaled on a stud 28 carried by the bracket I4, and fixedly secured to the gear 21 is a laterally projecting stud 29 providing an actuator for switch mechanism hereinafl tl described. The

ratio of the gearing described is such that the stud 29 makes one complete revolution in seven days.

Located adjacent the gear 21 is a disk 38 carried by a shaft 3|, journaled in the bracket l4, and the disk 30 is provided with a stud 32 to which 5 is pivotally secured one end of a lever 33 having a cam follower surface 34, which is periodically engaged by the moving stud 29, resulting in movement of the lever 33 to elevate the free end, holding the lever 33 in this position for a predetermined length of time.

The free end of the lever 33 is provided with fingers |34 embracing a sealed glass tube 35, containing a quantity of mercury 36 adapted to make and break electrical contact with electrodes 31, depending upon the inclination of the tube 35, and the resultant location of the mercury 36, either in or out of contact with the electrodes 31. The mercury 36 and electrodes 31 constitute a switch 38, which may be termed herein, a defrosting switch, electrically connected with a refrigerator motor 39, as shown in Figure 8, operating a cooling unit 4|! in the refrigerator 4|. The defrosting switch 38 is periodically actuated by movement of the stud 29 which periodically engages the cam surface 34 and rotates the defrosting switch 38 to an upwardly inclined position, as shown in Figure 4, thus instantly breaking the circuit to the motor 39 and inaugurating the defrosting period, and during this period the frost which has accumulated about the cooling unit 40 melts and defrosts the refrigerator 4|. The switch 38 remains in the defrosting position during the time required for the stud 29 to traverse the cam follower surface 34, and upon disengagement therewith the lever 33 drops to its lowered inclined position and closes the circuit, thus causing the motor 39 to operate.

The length of the defrosting period can be adjusted by rotating the knurled knob 42 carried by the shaft 3| which shifts the cam follower surface 34 with respect to the stud 29, varying the distance that the stud 28 traverses along the cam follower surface 34. To indicate the adjustment made in the defrosting period and the length of the defrosting period, an indicator 43 is rigidly secured to the shaft 3| adjacent the knurled knob 42, and is provided with a spring catch 44 adapted to engage the crimped edge 45 of an arcuate guide 46 mounted on the outer surface of the rear wall 41 of the casing l0, and the indicator 43 is adapted to register with an arcuate clock dial 48 carried on the outer surface of the rear wall 41.

In the embodiment herein described, we have shown only one stud 29 on the gear 21, but it is apparent that several studs may be secured to the gear 21, as at 10, to vary the interval of time between the defrosting periods, and also that the gear ratio effecting the periodicity of the stud 29 may be varied, and additionally, the instantaneous switch mechanism disclosed need not be a mercoid control switch.

Since the stud 29 completes one revolution in seven days, we provide means to set the clock 7 wire 5l, and a branch wire 52 leading to one of the terminals of the defrosting switch 38 and also connected to the line wire 53 by the branch 54. The circuit for the motor 39 includes a branch 55 having one end tapped into the branch 50 of the clock circuit, thus communicating with the :line wire 5!, and the other end is connected,

to the terminal of a thermostat switch 55 operation of which depends upon the temperature variations in the cooling unit 49, as is well known in the art, the other terminal of the switch 56 is connected to the motor 39 by means of the branch 57; and the other branch 58 of the motor circuit is'connected to the other terminal of the defrosting switch 38, and is adapted to make connection with the line wire 53 through the switch 38. Disposed in the rear wall 41 of the casing [9, are outlets 58 and 59, the former serving as a connection with the refrigerator motor 39, and the latter serving as an outlet for the wires 50 and 54 connected with the clock mechanism I3and leading to the line wires 5| and 53.

With this arrangement the clock is'operated independently of the motor 39; and operation of the defrosting switch 38, or the thermostat 56, does not effect the operation of the clock mechanism.

At the present time, mechanical refrigerators, according to our knowledge, are defrosted by manually turning off the. switch controlling the refrigerator motor; this however is very unsat isfactory, because if the frost is permittedto accumulate, it acts as an insulator to the passage of heat from the refrigerator, causing the refrigerator motor to operate more frequently and for a greater length of time, which increases the current consumption and consequently the cost of operating the refrigerator.

We have found that the length of the defrosting period required to completely defrost a refrigerator varies with the size of the refrigerator and surrounding conditions, however, for normal household use, a period of about five hours is required to completely defrost the refrigerator, provided the refrigerator is defrosted regularly once a week; the mechanism hereinbefore denscribed is operable to defrost once every seven days.

In operation, the desired defrosting period of five hours is effected by rotating the knurled knob 32 until the indicator 43 registers with the five-hour mark on the dial 48. When the moving stud 29 engages the cam follower surface 34, it will gradually elevate the defrosting switch 38 until the mercury 36 is out of contact with one of the electrodes 31, thus automatically breaking the circuit to the motor 39, and causingothe cooling unit 49 to cease its cooling operations. The cooling unit, 49 will remain inoperable for the indicated five hours, and at the end of this period the stud 29 moves out of engagement with the cam follower surface 34 and allows the defrosting switch 38 to drop to its lower inclined position, reestablishing the motor circuit. This defrosting operation will automatically be repeated at the same time of day. on the same day of each week for the same length of time.

It will be'apparent to those skilled in the art that the embodiment herein disclosed accomplishes at least the principal object of the invention, and that the construction is adapted to a,

wide variety of uses, and embodies advantages other than those herein disclosed, and also that the embodiment may be variously changed and modified without departing from the spirit or scope of the invention, and accordingly it will a be understood that the above disclosure isillus- V a lever having cam means, and carrying switch means, operable to makevand break a circuit when said lever is moved; actuating mechanism controlled by said clock mechanism for engaging said cam means and imparting actuating move. ment to said lever; and eccentric means supporting said lever and providing a fulcrum about which said lever moves, said eccentricmeans being adjustable to vary the period of engagement of said actuating mechanism with said cam means.

2. Timing mechanism of the character described, comprising: clock mechanism having clock-work and a dial for indicating thetime of the day; electric switch means including a lever having a cam thereon and carrying switch means adapted to be operated when said lever is moved; actuating means controlled by said clock-work for engaging said cam and imparting actuating movement to said lever; said electric switch means and said clock dial being juxtaposed, and simultaneously visible, to enable one to be checked against the other; and eccentric means supporting said lever and providing a fulcrum about which said lever moves, said eccentric means being adjustable to vary the time of engagement of said actuating mechanism with said cam.

RICHARD -H. CU'I'IING. WILLIAM E. RANEY. 

